A Multi-gate FET (MUGFET) is a family of MOSFETs in which more than one gate contact is used to control output current. MUGFETs are known to have superior gate control of the channel compare to single gate MOSFETs. For example, in a multigate device, the channel is surrounded by several gates on multiple surfaces, allowing more effective suppression of “off-state” leakage current. Multiple gates also allow enhanced current in the “on” state, known as drive current. These advantages translate to lower power consumption and enhanced device performance.
MUGFETs are one of several strategies developed to create ever-smaller microprocessors and memory cells, for example. In fact, many manufactures predict that MUGFET technologies will be the cornerstone of sub-32 nm technologies. The primary roadblock, however, to widespread implementation is manufacturability, as both planar and non-planar designs present processing challenges. These challenges may include lithography and patterning processes, as well as resultant high parasitic S/D resistance.
MUGFETs come in a variety of different architectures. For example, MUGFETs may be planar or non-planar devices. However, at sizes of, for example, 32 nm, planar transistors are expected to suffer from undesirable short channel effects, especially “off-state” leakage current. These off state leakage currents will increase the idle power required by the device. Nonplanar devices, on the other hand, are more compact than conventional planar transistors, enabling higher transistor density which translates to smaller overall microelectronics. But, a challenge to integrate non planar MUGFETs into conventional semiconductor manufacturing processes include, for example, fabrication of a thin silicon “fin” and of matched gates on multiple sides of the fin. Also, in conventional MUGFET devices, there is a large capacitance between the fins, which may result in decreased performance characteristics.
Accordingly, there exists a need in the art to overcome the deficiencies and limitations described hereinabove.